UDS and DPM not the same

Ide · January 7, 2022, 11:37

Hi, I'm fairly new to Ansys, I'm trying to model airflow though a room like a ventilation system. I made 2 rooms with a slightly different configuration with the same inlet flow and same volume so I assumed that for both rooms the mean residence time should be equal as RD=V/Q. However, when I calculated the DPM and UDS for the residence time of both rooms they all were different. I only thought variance would change. My question is why can the mean residence time change along with the different rooms as well as methods of calculation.

LuckyTran · January 7, 2022, 11:53

If you have a labyrinth/maze then the residence time can be really really really long. Volume/volumetric-flow-rate is a zero-dimensional model that doesn't take shape into account.

January 7, 2022, 11:37	UDS and DPM not the same	#1
Ide New Member Ide Join Date: Jan 2022 Posts: 1 Rep Power: 0	Hi, I'm fairly new to Ansys, I'm trying to model airflow though a room like a ventilation system. I made 2 rooms with a slightly different configuration with the same inlet flow and same volume so I assumed that for both rooms the mean residence time should be equal as RD=V/Q. However, when I calculated the DPM and UDS for the residence time of both rooms they all were different. I only thought variance would change. My question is why can the mean residence time change along with the different rooms as well as methods of calculation.

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January 7, 2022, 11:53		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,788 Rep Power: 66	If you have a labyrinth/maze then the residence time can be really really really long. Volume/volumetric-flow-rate is a zero-dimensional model that doesn't take shape into account.